The Biometry/Methodology Core is a centralized resource that provides direction and support for study design, data management, programming, computing, forms development, statistical analysis, psychometric testing, treating and supervision of interviewers, and the education of post- doctoral fellows and other trainees. The Core serves investigators primarily form the ARC, the Brigham and Women's Hospital, Harvard Medical School and Harvard School of Public Health. The Biometry Director and Executive Advisory Committee review and approve proposed projects. The Biometry staff advises on design and methodology and assesses feasibility by examining data sources, computer hardware and software configurations, data management plans, data collection mechanisms, sample size requirements, and analysis plans. This produces efficient likely to attain their goals. Thereafter, Biometry collaborates throughout the project, refining analyses and managing and documenting the data. Collaboration in projects provides extra benefits; experience gained and techniques developed in one study carry over to other studies, thereby achieving an economy of scale and stable research support by experienced methodologists with diverse skills.